1. Field of the Invention
The present invention relates in general to recording process and system for forming images utilizing a photosensitive sheet, and in particular to techniques for processing the exposed photosensitive sheet or a developer sheet, so that the image-bearing surface of an obtained recording sheet has dense visible images and/or improved glossiness. More particularly, the invention is concerned with such recording or image-forming process and system utilizing a photosensitive sheet which has light- and pressure-sensitive microcapsules.
2. Discussion of the Prior Art
An image transfer process or system which uses a photosensitive sheet having such microcapsules is known in the art. For example, each of the microcapsules forming a photosensitive coating on a substrate of the photosensitive sheet includes a radiation-curable base resin, and a chromogenic material which is supported by the base resin and is capable of reacting with a suitable developing material. The photosensitive coating is image-wise exposed to a radiation from suitable exposing means, according to source image information, so that the microcapsules are cured or left uncured, to form latent images on the exposed photosensitive sheet, according to the image information. In a subsequent developing process, the uncured microcapsules are ruptured by developing rollers, so that the chromogenic material comes out from the ruptured microcapsules, and reacts with the developing material, thereby forming visible images. The developing material is provided either as a developer layer formed on the substrate of the photosensitive sheet, or as a separate developer sheet which is superposed on the photosensitive sheet when the latent images on the photosensitive sheet are developed into the visible images on the developer sheet. In the former case, the photosensitive sheet is used as a recording sheet which is referred to as a self-activated type. In the latter case wherein separate photosensitive and developer sheets are used, the photosensitive sheet is used as an imaging sheet or transfer sheet, while the developer sheet is used as a recording sheet or copy sheet to which desired images are eventually transferred via the imaging sheet. This latter image transfer system is referred to as a separate type.
An example of the self-activated type of photosensitive sheet or photocopy sheet is disclosed in U.S. Pat. No. 4,440,846, and an example of the separate type of image transfer system is disclosed in U.S. Pat. No. 4,399,209.
In both cases indicated above, the image transfer system suffers from a problem which arises from a tendency that a rate of image-wise chemical reaction between the chromogenic material and the developing material is influenced by environmental conditions such as the ambient temperature, and the reaction rate is relatively low. Sometimes, it takes more than 30 minutes after the commencement of the chemical reaction, in order to allow the chemical reaction to continue until the obtained copy sheet is given a satisfactory level of image density.